Interior walls are formed by sheets of drywall material that are secured to the framing of a building. The seams between adjacent sheets of drywall material are taped, mudded, and sanded to obtain a substantially flat, smooth drywall surface. The drywall surface is coated with primer and paint to obtain a finished surface.
In some situations, a separate texture layer is applied to the drywall surface prior to painting. The texture layer is formed by spraying texture material onto the drywall surface. Texture material is a coating material that, when sprayed, does not form a smooth, thin coating. Instead, texture material is applied in discrete drops or globs that dry to form a bumpy, irregular textured surface.
Texture materials can be applied using any one of a number of application systems. During new construction, texture materials are commonly applied in a stream of compressed air using commercial hopper gun systems. For touch up or repair, texture material is commonly applied using hand operated pneumatic pumps or aerosol dispensing systems. Varying the parameters of the application system varies the size and spacing of the bumps to vary the look of the textured surface.
One specific form of texture material is commonly referred to as “acoustic” or “popcorn” texture material. In addition to a coating material, acoustic texture material further comprises an aggregate material. When the acoustic texture material is applied using commercial hopper guns, the aggregate material is conventionally formed by polystyrene chips. However, as will be described in detail below, chips made of polystyrene foam are dissolved by hydrocarbon aerosol propellant materials.
Accordingly, aerosol dispensing systems for dispensing small amounts of acoustic texture material for repair or touch-up purposes use one of two approaches. The first approach is to mix a liquid hydrocarbon aerosol propellant material with chips made from materials other than polystyrene. However, when chips made of materials other than polystyrene foam are used, the appearance and function of the texture surface may be different from that of the surrounding surface.
The second approach is to combine polystyrene chips with a propellant material formed by a pressurized inert gas such as nitrogen or air. This second approach allows the use of a conventional acoustic texture material including polystyrene chips. However, the use of a pressurized inert gas causes the acoustic texture material to be dispensed very quickly. The use of pressurized inert gas as a propellant can make it difficult for a non-professional to control the application of the acoustic texture material.
The need thus exists for improved systems and methods for dispensing small quantities of acoustic texture material for the purpose of touch-up or repair.